1. Field of the Invention
This invention relates to liquid-level float switches, specifically to a float switch and mounting system assembly of sturdy construction that is primarily contemplated for use in air conditioning condensate collection/overflow applications, or other applications where rising fluid beyond a threshold limit is undesirable and automated shut-off of the fluid source is needed to eliminate the risk of overflow and property damage. Currently used air conditioning condensate collection pans have many different upper edge configurations, thickness dimensions, and are made from a variety of plastic and metal materials. This has caused installers and repairmen to maintain a supply of at least several different float switch mounting systems, some adapting better to the thinner upper edge of metal condensate collection pans, and others more suited to the variable thicknesses found in existing plastic condensate collection pans. The location of the condensate collection pan also affects the type of shut-off switch used, as an attic environment can be subject to very high and very low temperature extremes. The goal of the present invention switch is provide one shut-off switch that can be quickly installed and is adaptable to all types and styles of currently existing condensate collection pans in air conditioning applications, including those with a thicker upper edge configuration and those with a slightly flared upper edge configuration. Further, since air conditioning condensate collection pans are often installed in hot attics, and other places where significant temperature fluctuations can occur, and also since many plastic condensate collection pans have insufficient construction whereby a float switch mounted on its upper edge will lean in over a period of time and no longer maintain the vertical orientation of shut-off switches mounted thereon that is needed for prompt and reliable switch operation, the present invention is also configured with an upper thumbscrew and external braces, internal ribs, and wings which strengthen the housing and minimize flexing to overcome the lean in problem. The most preferred embodiment of the present invention comprises an adjustable float switch body with the amount of its vertical movement relative to a concentrically positioned shaft being adjustably defined by an upper lock-nut connected to the threaded upper portion of the shaft upon which the float switch body moves, with the float switch body also having a large surface area for enhanced buoyancy and responsive operation. In addition, the most preferred embodiment of the present invention has a housing configured and positioned to protect float switch body movement from interference due to airborne debris, with the housing being closely positioned around the float switch body and having an open bottom end, the housing also having a threaded aperture centrally through its top surface that is configured for aligning the upper end of the shaft as it guides the vertical displacement of the float switch body within the housing, and the float housing further having at least one air vent opening through its rear wall (instead of through its top surface) that is configured and dimensioned to prevent float switch body malfunction as a result of an airlock created by fluid entering the float housing through its open bottom end. Further, the two-part housing/clamp structure of the most preferred embodiment of the present invention creates an inverted J-shaped slot configured for being positioned over the upper edge of a vertically-extending support surface, such as the upstanding wall of a plastic pan, with the back wall of the float housing (on the front part of the housing/clamp structure) forming one side of the slot and interior wall of the rear part of the housing/clamp structure forming the remaining part of the J-shaped slot, the rear part of the housing/clamp structure also preferably having at least two horizontally-extending lower threaded bores therethrough each configured for the engagement of one thumbscrew used for tightening the housing/clamp structure against a vertically-extending support surface positioned within its J-shaped slot for a secure connection of the two-part housing/clamp structure to its support surface and stabilization of the installed housing/clamp structure to prevent changes in its orientation that could diminish float switch body function. Vertically-extending internal ribs on both parts of the housing/clamp structure, in combination with the air vent holes in the rear wall/surface of the float housing, further assist in preventing airlock as fluid in the float housing rises prior to shut-off signal activation.
2. Description of the Related Art
When air conditioning condensate and other condensates are collected, there is often a risk of overflow and/or back-up into the system producing it. As a result, liquid-level float switches have been employed with collection pans to shut-off the source of condensate flow when the amount of fluid collected exceeds a predetermined depth considered safe in avoiding back-up or overflow. However, currently known float switches are deficient in many ways and thereby subject to malfunction, less responsive operation, more costly installation, and/or unstable installation. First, the collection pans used for condensate collection do not always have a sturdy construction. Therefore, when the upstanding pan wall to which a float switch is attached bends as a result of the added weight of the mounted switch, the pan wall tends to lean in over time and when it does the float switch body no longer maintains a level orientation, making it less responsive. Also, the plastic pans used in condensate collection applications can have varying upper edge configurations and a mounting bracket that securely attaches a switch/housing to a specific style of condensate pan so as to achieve proper float switch function, may not be able to become securely attached to a pan with a different upper edge thickness or configuration. This requires added expense for installers and repairmen when they must maintain a supply of at least several different float switch mounting systems, some adapting better to the thinner upper edge of metal condensate collection pans, and others more suited to the variable thicknesses found in existing plastic condensate collection pans. Further, depending upon the location of the collection pan, a float switch mounted thereto may be at risk for malfunction as a result of airborne debris, such as but not limited to the insulation fibers often encountered in attics where air conditioning system condensing units are commonly installed. Also, prior art liquid-level float switches tend to have float switch bodies that wobble relative to the shaft with which they are associated, a condition that can lead to less responsive operation or malfunction. Typically also, the installation of prior art float switches requires the drilling of at least one hole through the support surface or pan, which increases installation cost. In addition, some float switches are at risk for premature malfunction as a result of being made from materials that are not completely corrosion-resistant. In contrast, the present invention is made from plastic that is impervious to corrosion and pest-resistant. Its float switch body is wider than those of known prior art float switches for greater water displacement and a faster response, and it contains a housing that protects its float switch body from malfunction due to airborne debris. In addition, it has at least three thumbscrews to facilitate and expedite clamping member installation in as little as ten seconds, much faster than the prior art switch installation requiring the drilling of a hole in the condensate pan collection wall. Present invention thumbscrews additionally provide adjustability for better installation involving plastic pans. Further, a plurality of spaced-apart, vertically-extending internal ribs add strength to the present invention housing/clamp structure as well as provide air venting spaces therebetween to assist in preventing airlock as fluid rises within the float housing, external braces/ribs and lateral wings also add strength to prevent present invention flexing that could lead to lean in problems, and relocation of air vent holes from the top surface of the protective float housing to the back wall/surface of the protective float housing, which is in the front part of the housing/clamp structure, in combination with the vertically-extending, spaced-apart internal ribs that have venting spaces therebetween, protects the vent holes from airlock and makes them less likely to clog with water, algae, and/or debris for continued proper deployment of the float switch body within the housing during extended periods of use.